Oh, you're one of those. Everything is partisan politics to you.
If by "those" you mean a MAGA-loving Roman Catholic, then yes, I'm one of "those."
I know its hard for some to imagine, but RPG system preference is largely unconnected from politics.
4E delivered on my itch for interesting and mechanically supported martial classes who didn't need to rely on magic items to function (as soon as 4E introduced inherent bonuses we never used anything else) and spellcasters that worked more like they do in pop culture in a way even better than Palladium Fantasy could... thus my love for 4E.
Nor is it partisan or political to examine broad-based cultural influences on game system development. People of every political spectrum read Harry Potter and watched the Lord of Rings films growing up. People of every political spectrum watched Buffy (and funny how the whole addiction angle only turned up in season six then all-but disappeared in season seven and no other spellcaster in either it or Angel demonstrated addiction issues) and went to see Dr. Strange (another example of modern perceptions on magic).
Frankly, every 4E fan I've ever met personally has been exclusively on the right side of political issues and the only TSR fans I know personally are neck-bearded old Lefties (I don't know any OSR fans personally... its just not a thing in my part of the country; if you want old school you just play AD&D or BECMI).
As to Harry Potter, I think the author ran out of steam in Book Five and caved to the loudest fan theories for the conclusion, so I don't necessarily blame you for not having read it (I doubt it will age as well as Tolkien has), but to thereby pretend it had no cultural impact and therefore should not influence the most popular fantasy RPG on the market feels a little on the myopic side.
In terms of pros and cons, the primary pro which has definitely entered every version of D&D since late 3.5e brought us reserve feats is basic at-will combat spells that are fired off with one or two word phrases and a simple gesture with their focus/implement. Most spell combats play out more like gun fights than anything, just with effects like paralysis or unconsciousness or burns more common than outright death (until the main villains finally show up starting around Goblet of Fire and the use of killing curses by them get more prevalent). In terms of use limit, you get tired eventually, but no more so than swinging a sword or firing a bow repeatedly would.
The primary con of the system in Harry Potter is that its essentially skill based. You have to know the words and gestures and be able to perform them precisely in order to bring about an effect. Do it incorrectly and at best nothing happens, at worst you or the target suffer various magical mishaps (one example was an less skilled wizard tried to mend a broken bone and instead removed all the bones from the subject's arm).
A related con is that you need a particular implement (a specially constructed wand in the case of Harry Potter) to reliably perform magic. Wandless magic is possible, but extremely difficult (akin to a -20 to your Use Magic check). Thus, disarming a wizard of their wand can also put them out of a fight.
A less obvious con of the system is that its somewhat genetic-based. You're either a born wizard/witch or you're not. If you're not you could perform a spell perfectly and nothing will happen. If you are then untrained young wizards sometimes cause spontaneous magic by accident.
As WWoW points out, its not an entirely coherent system of magic in the sense that there's zero attempt at any sort of balance or explanation of its origins or why doing X produces Y results, but fans of the series could still take a look at the AD&D wizard and say "there is no way I can create my House Ravenclaw style PC" while they could take a look at the 4E or 5e wizard and absolutely see how the basics of emulating the HP-style casting in the system would work.